Arctic Is Heating Up Twice as Quickly as Rest of World

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Bad news for polar bears: The Arctic is still warming at twice
the pace of the rest of the planet, according to a new federal
report.

Last year, air temperatures in the northernmost regions of the
globe were, on average, 1.8 degrees Fahrenheit (1 degree Celsius)
higher than normal. Unusually warm years like 2014 have only
become more frequent in the Arctic in the
past decade, even as the rate of temperature increase slowed for
the rest of the world.

In 2014, the Greenland Ice Sheet's heat-deflecting brightness hit
a low; spring snow cover dwindled to record lows in Eurasia;
polar regions had a below-average extent of summer sea ice, and
as for the polar bears that depend on that ice to survive, some
populations have declined, according to the report. [ See
Stunning Photos of Earth's Vanishing Ice ]

The findings are included in the National Oceanic and Atmospheric
Association's (NOAA) annual " Arctic Report Card,"
a comprehensive review of the North Pole's health that is
assembled by more than 60 scientists.

"Climate change is having a disproportionate effect on the
Arctic," Craig MacLean, NOAA's acting assistant administrator for
the office of oceanic and atmospheric research, said in a news
briefing today (Dec. 17) at the 47th annual meeting of the
American Geophysical Union in San Francisco. "For the past 30
years, the Arctic has been getting greener, warmer and
increasingly more accessible to shipping, energy extraction and
fishing."

A trend of warming

Unlike past report cards, this year's polar checkup didn't reveal
any major broken records. But this year's data fits in with the
"persistent warming" trend that scientists have been observing in
the Arctic for more than three decades, said Jacqueline
Richter-Menge, of the U.S. Army's Cold Regions Research and
Engineering Laboratory.

From October 2013 to September 2014, the average surface air
temperature in the Arctic was 1.8 degrees F (1 degree C) above
the 1981-2010 average. The amount of sea ice floating in the
Arctic in September 2014 was the sixth lowest since satellites
began recording such data in 1979, the report found. Though the
Greenland
Ice Sheet had essentially the same mass in 2014 as it did in
2013, its reflectivity, or
albedo, hit a record low in August. (Records only began for
this effect in 2000.)

The Arctic warms at a higher rate than lower latitudes because of
a well-documented effect known as Arctic amplification of global
warming, Richter-Menge told reporters. Arctic amplification is a
self-feeding cycle. Because of their light color, sea ice and
snow bouncs radiation from the sun back into the atmosphere. But
when more ice and snow melta, more of the dark-colored patches of
earth and ocean are exposed, locking more heat into the
already-warming planet's surface.

Kinky jet streams and missing polar bears

Rising temperatures in the Arctic are thought to affect the rest
of the planet. Some research has suggested that warming around
the North Pole can cause the typical path of the jet
stream to go haywire, though scientists have yet to
reach a consensus. Without data for a long period of time, it's
difficult to tell whether this phenomenon is really a trend or
part of the "normal chaos" of the atmosphere, said James
Overland, an oceanographer with NOAA's Pacific Marine
Environmental Laboratory. Regardless of the cause, a wavy jet
stream can have a huge influence on weather, the report
illustrates. For example, a
twisted jet stream led to remarkable temperature spikes in
Alaska in January, when the region experienced temperatures as
much as 18 degrees F (10 degrees C) higher than normal.

This year's Arctic Report Card also included a special paper on
polar bears that found the species has experienced a major
decline in Hudson Bay, Canada, because of sea-ice loss. (Bears
use these floating ice platforms to travel, hunt and look for
mates.) The number of females in this region dropped from 1,194
to 806 between the years 1987 and 2011.

But, the news was sunnier for polar
bears in other regions. For example, the population of polar
bears in the Beaufort Sea, north of Alaska, declined by as much
as 50 percent a decade ago. But now, the population seems to have
stabilized at about 900, according to the report.